The present invention relates generally to thermal management and specifically to personal thermal management systems. Thermal comfort is a term created by psychologists; nevertheless the term has a physiological basis and can be considered to be identical with the term optimum temperature. Thermal comfort and discomfort typically reflects both internal (core) and external (skin) temperature sensitivity and the central integration of these two loops. When dealing with textile and allied assemblies, as in clothing, the factors contributing mainly to the external loop of the thermal comfort sensation are typically at play.
Skin is an organ that has a special role, as it is typically not only the source of information by virtue of comfort sensors, but the interface between the thermal core of the body and the environment. The human body attempts to maintain core body temperature around 37° C. The balance between perspiration and heat productions by the body and loss of the same may be defined as the “comfort” factor. The body is typically in a state of comfort when its temperature is about 35° C. and there is little to no moisture present on the skin. Heat exchange with the environment plays a key role in the thermal state of the human body. Thermal comfort may be defined as that condition of mind which expresses satisfaction with the thermal environment. Due to individual differences, specifying a thermal environment that will satisfy the thermal comfort of all can be a challenge.